ALMA Special Session AAS 245
New perspectives on protoplanetary disks in the era of JWST and the ALMA Wideband Sensitivity Upgrade
The NAASC will host a special session at the upcoming 2025 245th Winter AAS Meeting in Washington DC. This special session will present recent high-impact ALMA and JWST results in different subfields of protoplanetary disk studies, and introduces how future synergistic experiments enabled by the transformative capabilities increase from ALMA-WSU will support the next revolution in the field.
The session will include 4 invited talks by M. Van 't Hoff (Purdue University), C. Espaillat (Boston University), K. Pontoppidan (JPL), K. Zhang (Wisconsin) and a short general presentation of the WSU.
Abstract:
ALMA observations have been the basis for a revolution in the understanding of the structure and gas composition of protoplanetary disks, thanks to its ability to probe emission from embedded and/or cold regions. This new paradigm has now been leveraged by results from JWST uniquely characterizing dust and ice grain size distribution and composition in inner disks, unveiling the processing of water and hydrocarbons. Together, such observations can paint a 3-D view of the general vertical structure in a number of disks at different evolution stages. Most recently, ALMA and JWST data have provided characterization of ongoing processes at the scale of embedded planets and protoplanets, such as direct evidence of gravitational instabilities, gas and dust accretion onto planetary cores, planet-driven outflows and planetesimal growth from molecular freeze-out on dust grains. As a detailed and nuanced picture is emerging of the processes driving the formation and evolution of protoplanetary disks, the next step would be to establish the framework linking the spectral type and multiplicity of hosts stars to the structure of their planetary systems and the composition of planetary atmospheres.
When JWST approaches the end of its planned mission lifetime, ALMA will have completed the first phase of a major upgrade of its components - the Wideband Sensitivity Upgrade (WSU), consisting of a completely new digital path, correlator, and three new wideband receivers - with additional receiver bands to follow. For protoplanetary disks, this comprehensive upgrade translates into much more effective spectral surveys for extensive molecular gas composition characterization, increased image fidelity and sensitivity for the detailed identification of disk substructures and kinematic distortions, and overall access to a much larger number of targets, including compact disks, for a better sampling of the variety of disk sizes and evolution stages.
